1. Technical Field to Which the Invention Belongs
This invention relates to apoptosis inducers, anticancer drugs and carcinostatic drugs which are usable as medicines. It further provides a method for inducing apoptosis which is useful in, for example, clarifying the mechanism of apoptosis and screening apoptosis induction inhibitors. Furthermore, it provides purified sulfated-fucose-containing polysaccharides and degradation products thereof and a sulfated-fucose-containing polysaccharide degrading enzyme which is useful in producing sulfated-fucose-containing polysaccharide degradation products and studying the structures thereof.
2. Description of the Related Art
In recent years, the style of apoptosis (self-destructive cell death or suicidal cell death) has attracted attention regarding the death of cell tissues.
It is considered that apoptosis is the death inherently programmed in genes, different from necrosis meaning pathological cell death. Namely, some external or internal factors trigger the activation of genes programming apoptosis. On the basis of this genes, a programmed death gene protein is subsequently biosynthesized and decomposed the cells per se, thus causing death.
It is highly meaningful to express the apoptosis in a desired tissue or cells, if possible, since unnecessary or pathogenic cells can be spontaneously eliminated from the living body thereby.
The present invention aims at developing highly safe compounds having effects of inducing apoptosis and thus providing apoptosis inducers, anticancer drugs and carcinostatic drugs containing these compounds and a method for inducing apoptosis by using these compounds as the active ingredient. The present invention further aims at providing an enzyme capable of degrading the compounds of the present invention which is useful in the production of the degradation products of these compounds.
In summary, the first invention of the present invention relates to apoptosis inducers which contain sulfated-fucose-containing polysaccharide(s) and/or degradation product(s) thereof.
The second invention of the present invention relates to a method for inducing apoptosis which comprises using as the active ingredient sulfated-fucose-containing polysaccharide(s) and/or degradation product(s) thereof.
The third invention of the present invention relates to anticancer drugs containing sulfated-fucose-containing polysaccharide(s) and/or degradation product(s) thereof of the fifth or sixth invention of the present invention.
The fourth invention of the present invention relates to carcinostatic drugs containing sulfated-fucose-containing polysaccharide(s) and/or degradation product(s) thereof.
The fifth invention of the present invention relates to sulfated-fucose-containing polysaccharides having the following physicochemical properties:
(1) constituting saccharide: containing uronic acid; and
(2) being degraded by the fucoidanase produced by Flavobacterium sp. SA-0082 (FERM BP-5402) to thereby form at least one of the compounds selected from those represented by the following formulae (I), (II) and (III): 
The sixth invention of the present invention relates to sulfated-fucose-containing polysaccharides having the following physicochemical properties:
(1) constituting saccharide: substantially being free from uronic acid; and
(2) substantially incapable of being degraded by the fucoidanase produced by Flavobacterium sp. SA-0082 (FERM BP-5402).
Thee seventh invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the fifth invention of the present invention which involves the step of treating a mixture of sulfated-fucose-containing polysaccharides with a chemical capable of aggregating acidic polysaccharides in the presence of salts and eliminating the precipitate.
The eighth invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the fifth invention of the present invention which involves the step of treating a mixture of sulfated-fucose-containing polysaccharides with an anion exchange resin in the presence of a divalent cation to thereby take up the target polysaccharides.
The ninth invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the fifth invention of the present invention which involves, in the process of producing the sulfated-fucose-containing polysaccharides of the fifth invention of the present invention, the step of eliminating the coexisting coloring matters by using a polysaccharide substance or a substance having an anion exchange group.
The tenth invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the sixth invention of the present invention which involves the step of treating a mixture of sulfated-fucose-containing polysaccharides with a degrading enzyme capable of degrading sulfated-fucose-containing polysaccharides containing uronic acid or a microorganism having this enzyme to thereby take up the target sulfated-fucose-containing polysaccharides.
The eleventh invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the sixth invention of the present invention which involves the step of treating a mixture of sulfated-fucose-containing polysaccharides with a chemical capable of aggregating acidic polysaccharides in the presence of salts to thereby precipitate the target polysaccharides.
The twelfth invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the sixth invention of the present invention which involves the step of treating a mixture of sulfated-fucose-containing polysaccharides with an anion exchange resin in the presence of a divalent cation to thereby take up the target polysaccharides.
The thirteenth invention of the present invention relates to a process for producing sulfated-fucose-containing polysaccharides of the sixth invention of the present invention which involves, in the process of producing the sulfated-fucose-containing polysaccharides of the sixth invention of the present invention, the step of eliminating the coexisting coloring matters by using a polysaccharide substance or a substance having an anion exchange group.
The fourteenth invention of the present invention relates to a process for producing a sulfated-fucose-containing polysaccharide mixture which comprises effecting the extraction of sulfated-fucose-containing polysaccharide mixtures to be used in the seventh, eighth, tenth, eleventh or twelfth invention of the present invention from marine algae in the coexistence of acetate and calcium ions.
The fifteenth invention of the present invention relates to an endo-sulfated-fucose-containing polysaccharide degrading enzyme having the following physicochemical properties:
(i) function: acting on sulfated-fucose-containing polysaccharides having the following physicochemical properties and degrading the sulfated-fucose-containing polysaccharides:
(a) constituting saccharide: substantially being free from uronic acid; and
(b) substantially incapable of being degraded by the fucoidanase produced by Flavobacterium sp. SA-0082 (FERM BP-5402);
but not acting on sulfated-fucose-containing polysaccharides having the following physicochemical properties:
(c) constituting saccharide: containing uronic acid; and
(d) being degraded by the fucoidanase produced by Flavobacterium sp. SA-0082 (FERM BP-5402) to thereby form at least one of the compounds selected from those represented by the following formulae (I), (II) and (III): 
(ii) optimum pH value: being from about pH 7 to 8; and
(iii) optimum temperature: being from about 30 to 35xc2x0 C.
The sixteenth invention of the present invention relates to an enzyme composition containing a calcium source and an endo-sulfated-fucose-containing polysaccharide degrading enzyme of the fifteenth invention of the present invention.
The seventeenth invention of the present invention relates to a process for producing an endo-sulfated-fucose-containing polysaccharide degrading enzyme of the fifteenth invention of the present invention which comprises incubating an Alteromonas capable of producing the endo-sulfated-fucose-containing polysaccharide degrading enzyme of the fifteenth invention of the present invention and recovering the enzyme from the culture medium.
The eighteenth invention of the present invention relates to degradation products of sulfated-fucose-containing polysaccharides obtained by treating sulfated-fucose-containing polysaccharides of the sixth invention of the present invention with an endo-sulfated-fucose-containing polysaccharide degrading enzyme of the fifteenth invention of the present invention.
The present inventors have successfully obtained various purified sulfated-fucose-containing polysaccharides and degradation products thereof and subsequently examined biological activities of these substances. As a result, they have found out that these substances induce apoptosis of cancer cells and have potent anticancer effects. They have further found out that the sulfated-fucose-containing polysaccharides and/or degradation products thereof have potent carcinostatic effects. They have furthermore succeeded in the isolation of an enzyme capable of degrading sulfated-fucose-containing polysaccharides and being useful in the preparation of the degradation products of the present invention, thus completing the present invention.